Antitarnishing material for silverware and other metals and process of producing the same



Patented eb. 13, 1934 UNITED STATES ANTITARNISHING MATERIAL FOR SILVER-WARE AND OTHER METALS AND PROCESS OF PRODUCING THE SAME Arthur E.Thurber and Raymond H. Sholtz, Sherrill, N. Y., assignors to OneidaCommunity,

Limited, Oneida, N. Y., a corporation of New York No Drawing.Application December 9, 1931,

Serial No. 579,982. Renewed May 12, 1933 10 Claims.

The present invention has for its objects, first, to provide a materialwhich can be used in the ordinary ways for wrapping or otherwiseenclosing articles consisting of or containing silver or other sensitivemetal and which will also be inert or inactive as to any tarnishingeffect in or on such articles and at the same time protect them againstthe tarnishing effects of the atmosphere, and, second, to provide asuitable process for the economical production of such material.

Many suggestions have heretofore been made looking towards the provisionof such a material, some of them having to do with a material, such aspaper, which is freeof injurious sulphur com- 16 pounds and othershaving to do with the impregnation of such material with certain metalsalts and other substances for protecting the articles against thetarnishing effects of the atmosphere. Such a sulphur-free material, andmore particu- 20 larly paper, is open to the objection that it is verycostly to produce and that the processes used in its production oftenresult in a loss of or reduction in the strength of the material, thisbeing particularly true in the case of paper in the 2 form of sheets,pasteboard, cardboard, etc.

The present invention has to do with paper and other materials, in themanufacture or the bleaching of which sulphur compounds are used andwhich, as a result, are impregnated with injurious sulphur compoundswhich render them useless for wrapping or otherwise enclosing silverwareor other tranishable metal articles unless these sulphur compounds beremoved by chemical treatment, which'is costly and also objectionablebecause of the weakening of the material, particularly paper, or suchsulphur compounds-be rendered inert or inactive as to effect, if thiscan be done effectively and without substantial additional cost of thefinal material or 4 the weakening of it in strength.

We have discovered that paper and other materials containing sulphurcompounds can be treated so as to render their sulphur compoundsinactive or inert as to tarnishing effect and that they may be sotreated that the material will also protect the silver against thetamishing effects of the atmosphere, and that all this may be donewithout any substantial increase in-the cost of the material and withoutany loss of or reduction in its strength.

According to our present invention the sulphur compounds of the paper orother material are rendered inactive as to tarnishing effect by theaddition of a soluble salt of copper (preferably copper sulphate) thisaddition having the effect of decomposing the injurious sulphurcompounds of the paper or other material and precipitating the sulphuratoms in an inactive and inert form, the quantity of copper sulphate orother soluble copper compound used being, of course, sufficient for suchdecomposition and precipitation, and preferably in excess thereof forthe purpose which will be hereinafter stated.

The paper or other material may be so treated for the decomposition ofthe injurious sulphur compounds and the precipitation of the sulphuratoms either during the process of manufacturing the paper or othermaterial or after its manufacture has been completed. We prefer,however, that thetreatment should occur during the process ofmanufacture because it is more economical to do so and also because abetter diffusion or dissemination of the soluble copper compound ispossible than is possible if the treatment occur after completion ofmanufacture.

In the manufacture of non-tarnishing paper, pasterboard, cardboard andother materials, we

preferably add copper sulphate in suitable con-- centration to the paperwhile it is being manufactured, such addition, in the case of paper,being preferably made to the pulp while it is in the beater as thisinsures a more thorough mixing of the copper sulphate with the pulp anda longer time for the reaction between it and the sulphurcompounds inthe pulp. We also prefer to maintain a temperature in excessof 130Fahrenheit in the beater and, where a batch beater is use, to retain thepulp in the beater for at least one hour after the addition of thecopper sulphate. The quantity of copper sulphate must, of course, besuflicient to decompose the injurious sulphur compounds present andprecipitate the sulphur atoms in the paper and should preferably be inexcess thereof to provide for a certain quantity of the copper sulphatein the finished paper to protect the silver or other metal articlesagainst the tarnishing effects of the atmosphere; About fifty pounds perton of finished paperstock have been found to be sufficient.

In the case of certain textile materials in the bleaching of whichsulphur compounds are used, we prefer to add the copper sulphate to thematerials during their manufacture for the reasons stated as to paper.

In the case of paper and other materials the addition of the coppersulphate or other soluble copper compound may be made in the finishedpaper or other materials, if desired, without departing from the presentinvention.

The anti-tarnishing paper, pasteboard, cardboard and the like, and theanti-tarnishing textile material may be used in many different forms andfor many different purposes and the articles to be protected may also bein many different forms. For example, the paper, etc., and the textilematerial may be used as wrapping for the articles or as interleavesbetween sheets, nests or layers thereof such as sensitized photographicplates or films or as linings for chests or similar receptacles for thearticles or as strips-in which to roll the articles or for themanufacture of boxes, bags, and other containers for the articles.

What we claim is:

1. As a new article of manufacture, paper or other material the sulphurcompounds of which have been rendered inactive as to tarnishing effeeton silver or other tarnishable metals by the use of a soluble coppercompound.

2. As a new article of manufacture, paper or other material the sulphurcompounds of which have been rendered'inactive as to tarnishing effeeton silver or other tarnishable metals by the use of a soluble coppercompound and which has an excess or such copper compound for protectingthe silver or other metal against the tarnishing effects of theatmosphere. g

3. As a new article of manufacture, paper or other material the sulphurcompounds of which have been rendered inactive as to tarnishing effecton silver or other tarnishable metals by the use of a copper sulphate.

4. As a new articleof manufacture, paper or other material the sulphurcompoundsof "which .have been rendered inactive as to tarnishing effeeton silver or othertarnishable metals by the use of a copper sulphate andwhich has an excess of such copper sulphate for protecting the silver orother metal against the tarnishing effects of .the atmosphere.

5. The process of treating paper or other materials to render themnon-tarnishing as to silver or other tarnishable metals which consistsin rendering the sulphur compounds thereof inactive as to tarnishing bythe addition of a soluble copper compound during the manufacture of thepaper or other material.

6. The process of treating paper or other materials to render themnon-tarnishing as to silver or other tarnishable metals which consistsin rendering the sulphur compounds thereof inactive as to tarnishing bythe addition of a copper sulphate during the manufacture of the paper orother material.

7. The process of treating paper, pasteboard, cardboard or the like torender it non-tarnishable as to silver or other tarnishable metals whichconsists in rendering the sulphur compounds thereof inactive as totarnishing by the addition of a soluble copper compound to, the paperpulp.

8. The process of treating paper, pasteboard,.

cardboard or the like to render it non-tarnishable as to silver or othertarnishable metals which consists in rendering the sulphur compoundsthereof inactive as to tarnishing by the addition of. copper sulphate tothe paper pulp.

9. As a new article of manufacture, paper or other material containing asoluble copper compound for protecting silver or other sensitive metalsagainst, the tarnishing effects of the atmosphere.

10. As a new article of manufacture, paper or other material containingcopper sulphate for protecting silver or other sensitive metals againstthe tarnishing effects of the atmosphere.

- ARTHUR E. THURBER'. RAYMOND H. SHOLTZ.

